Ruthenium(IV)-oxo complexes: the novel utilization of tertiary pnictogen ligands
Ruthenium(IV)-oxo complexes: the novel utilization of tertiary pnictogen ligands
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钌(IV)-氧配合物：三级磷配体的新用途
DOI：
10.1021/ja00213a019
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发表时间：
1988
影响因子：
15
通讯作者：
K. Takeuchi
中科院分区：
文献类型：
--
作者：
M. Marmion;K. Takeuchi
新型配合物((bpy)/sub 2/(PnR/sub 3/)Ru/sup IV/(O))(ClO/sub 4/)/sub 2/（其中bpy = 2,2'-联吡啶，PnR/sub 3/ =叔膦或胂）由类似的钌(II)-水基物通过电化学手段或通过添加两等量的铈（IV）生成。通过紫外可见光谱、红外光谱、/sup 18/O标记实验、核磁共振光谱、循环伏安法、库仑法和电导率测量完成了钌(II)-水络合物和钌(IV)-氧络合物的表征。这些配合物在固态和各种溶液中都是稳定的，其中膦和胂配体不会被钌(IV)-氧中心氧化。钌(II)-水络合物的循环伏安测量结果与以下氧化还原对一致：Ru/sup IV/ = ORu/sup III/ - OHRu/sup II/ - OH/sub 2/，这可以描述为两组伴随的单电子、单质子转移。钌(IV)-氧配合物作为有机底物的选择性氧化试剂，其中烟原配体的性质极大地影响了底物的氧化速率。此外，与其他钌基氧化剂相比，在这些配合物中使用顺式氧基配体简化了底物氧化的机制。最后，烟原配体对钌(IV)-氧配合物的氧化还原化学产生了不同寻常的影响，包括疏水选择性和更多的好氧驱动的底物氧化催化。«少
The novel complexes ((bpy)/sub 2/(PnR/sub 3/)Ru/sup IV/(O))(ClO/sub 4/)/sub 2/ (where bpy = 2,2'-bipyridine and PnR/sub 3/ = tertiary phosphine or arsine) have been generated from the analogous ruthenium(II)-aquo species, through electrochemical means or by the addition of two equivalents of cerium(IV). Characterization of the ruthenium(II)-aquo and ruthenium(IV)-oxo complexes was accomplished through UV-vis spectroscopy, IR spectroscopy, /sup 18/O labeling experiments, NMR spectroscopy, cyclic voltammetry, coulometry, and conductivity measurements. These complexes are stable both in the solid state and in various solutions, where the phosphine and arsine ligands do not undergo oxidation by the ruthenium(IV)-oxo center. Cyclic voltammetric measurements of the ruthenium(II)-aquo complexes are consistent with the following redox couples: Ru/sup IV/ = ORu/sup III/ - OHRu/sup II/ - OH/sub 2/, which can be described as two sets of concomitant one-electron, one-proton transfers. The ruthenium(IV)-oxo complexes act as selective oxidation reagents toward organic substrates, where the nature of the pnictogen ligand greatly affects the rate of substrate oxidation. In addition, the use of a pnictogen ligand cis to the oxo moiety in these complexes simplifies the mechanism of substrate oxidation relative to other ruthenium-based oxidants. Finally, pnictogen ligands exert unusual effects on the redox chemistry of ruthenium(IV)-oxo complexes, including hydrophobic selectivity andmore » aerobically driven substrate oxidation catalysis.« less